Not sure I'm so enthused with the NTM Mike
Agree that when the tyres are cold or at operating temperature the model feels better but I can't understand the total loss of all grip when one gets just a little hotter. Ok, I've never driven a slick shod car so have no RW experience but it just doesn't seem right. It appears only a very small mistake is enough to flip the grip switch to.
That is apparently how the real NASCAR tyres behave. Their best grip is when cold, then they drop off a bit as they come up to temp. Because it's a heavy car, sliding around heats up the tyres very quickly and grip drops off a lot.
The more conventional road course tyres will behave very differently. Less grip until you get them up to temp, possibly more forgiving of sliding around but over-do it and grip will drop.